Image-guided interventional radiology: The journey so far…

Bhavna Sahu

Recently, one of my siblings happened to be diagnosed with increased heartbeat, ‘tachycardia’, as we say in medical terms. Apprehension in the family rose when the episodes of tachycardia became more frequent. So, the family landed up in a multi-speciality hospital and consulted a cardiologist. Post all routine investigations, the heart was subjected to an electro physiology (EP) study, wherein it was mentioned to the family that in case there is an extra outlet of electrical activity outside or near the heart, it will be taken care of by burning the outlet. To the patient as well as his family, who were completely unaware about the procedure, it was like a minor psychological shock leading to an assumption that some burning near heart is going to be a great deal of surgery. But, thanks to the innovations in technology most of the surgeries have been reduced to  just a few minor cuts and few days of hospital stay. The effect of the same also reflects in terms of reduced hospital expenses. And, the bottom line is that walk-in individuals can walk out individually, post their surgeries.

With constantly changing trends in healthcare as well as advancements in technology and instrumentation, trail blazers are the institutions who adapt to the change and walk ahead towards changing the present day scenario while persistently overcoming the pit-falls in the path of healthcare delivery. Image-guided interventions are one such recent advancement in the field of surgery. Thriving in almost every surgical procedure, image guided radiology is assumed to have assisted in increasing the number of patients opting for such kind of surgeries. It is also presumed that the cause of its increasing popularity is a direct effect of it ensuring  minimal scar and pain and condensed hospital stay.

Actually, interventional radiology (IR) is a medical sub-speciality of radiology which makes use of
minimally-invasive image-guided procedures for diagnosis and treatment of diseases. Premise of IR relies on the diagnosis and treatment of patients by minimal incisions, minimal risk and improved health outcomes. Utilising the radiological imaging modalities like X-ray, CT scan, ultra-sonography, MRI, etc., the preoperative or intra-operative images are then employed by surgeons as the guide to the procedure. Vast number of surgical interventions like cancer surgeries, percutaneous biopsies, gastrointestinal interventions, spinal interventions, angiographies, angioplasties, tumour ablations, peripheral vascular interventions, etc., which required major surgical procedures are nowadays being treated by interventional radiologists and surgeons in a day or two using non-surgically/minimally invasive procedures. By minimising the physical trauma to the patient, peripheral interventions can also reduce infection rates and recovery time, as well as shorten hospital stays.

DVT thromobosis	Endovenous laser ablation

Great innovations from the past

More than 30 years have been invested in the growth and development of the minimally invasive surgeries and it is evident with recent advancements in the field that now they have become commonplace in the world of medicine and surgery. The first development in IR occurred with the invention of angioplasty and the catheter-delivered stent, which were first used to treat peripheral arterial disease. Since then, IR has come a long way.

Charles Dotter, MD is known as “Father of Interventional Radiology” for pioneering techniques in interventional radiology. And it was Alexander Margulis who coined the term “interventional” for the new, minimally invasive techniques. He laid emphasis on the point that innovation should be achieved through training, technical skill development, clinical knowledge acquisition, and superior patient care in close coordination with surgical and medical doctors and their teams.

This was then followed by development of stents. Revolution in the field of medicine and cardiology was earmarked by coronary artery angioplasty and stenting. Post initiation of selective vasoconstrictive infusions by Baum, Josef Rösch brought in selective arterial embolisation as one of the procedures to control the uncontrollable bleeding in the early 70s. Gastrointestinal (GI) bleeding treatment then became a tell tale in the medical fraternity. In mid-70s using transhepatic variceal embolisation technique Anders Lundequist was successfully able to treat variceal bleeding. The 1980s marked interventions in the biliary tract with the development of special tools and devices for biliary manipulation. Biliary bypass surgery was aided with biliary stents by Plinio Rossi and Hall Coons. Joachim Burrhenne, Interventional Radiologist invented and mastered the percutaneous removal of retained biliary stones technique. For improvement of blood flow in cases of liver damage in conditions of cirrhosis and hepatitis C– transjugular intrahepatic portosystemic shunt (TIPS) was invented.

Percutaneous uroradiologic interventions like percutaneous kidney/ gall bladder stone extraction, nephrostomy drainage, and urethral stenting were brought in by the innovations of interventionalists Kurt Amplatz, Willi Castaneda and Dave Hunter. 1990s were the time when interventional oncology was pioneered with the introduction of radiofrequency ablation (RFA) technique for liver tumours, soft tissue tumours (bone, breast, kidney, lung and liver cancer) and embolisation for treatment of bone and kidney tumours. Embolisation techniques for pulmonary AVMs were pioneered by Bob White. Treatment for bone and kidney tumours by embolisation and treatment of disseminated liver metastases was done by Sid Wallace. In 1991, abdominal aortic stent grafts were introduced which was then followed by balloon expandable coronary stent, intra-arterial delivery of tumour-killing viruses and gene therapy vectors to the liver, percutaneous delivery of pancreatic islet cells to the liver for transplantation to treat diabetes and development of the endovenous laser ablation procedure for treatment of varicose veins and venous disease.

The present

Over the last few years, emphasis has been to minimise the number of incisions and the same has become a reality today with image-guided IR. Today, many conditions that once required surgery can be treated non-surgically by interventional radiologists. A small knick using miniature catheters and instruments is made and the treatment is done, which saves a patient from open invasive surgery. Minimally invasive procedures are used in all fields of medicine and surgery, especially in general surgery, medical oncology, radiation oncology, cardiology, hepatology, and gastroenterology.

In present times, image-guided IR has its utility in all minimally invasive surgeries as well as major surgeries. The vast range of which could be listed as laparoscopy, angiography (CT guided – CTA/ MR assisted – MRA), angioplasty, drainage procedures, per cutaneous tumour ablations, radiotherapy, embolisation, CT guided biopsies, peripheral vascular interventions, intramuscular psychotherapy, balloon angioplasty, angioplasty, and implantation of drug eluted stets, spinal interventions – vertebrate, treatment of thrombi-embolism by using retrievable inferior vane cave (IVC) filters, treatment of vascular disorders by ablations, and many more.

These procedures have become substitutes to the conventional procedures, diagnostics and major surgeries. Though all procedures involve risk, the minimally invasive ones are found to have minimal risks and rapid recovery time. Image-guided IR techniques and procedures are the best alternatives when surgeries of certain type involve high risks when operated using conventional methods. Unlike catheter hagiography, noninvasive CTA and MRA are less risky to patients and facilitate rapid diagnosis.

Innovations for future

What the future holds for the fields of surgery can be foreseen. With the rapid advancements in technology and interventions, it can be ascertained that image-guided interventions will drive the medical and surgical fields.

Radiology is capital and labour-intensive. In this era of healthcare reforms and budget restrictions, long-term planning becomes a need of the hour. IR’s cost-effectiveness has allowed its widespread deployment. The process of diagnosis and treatment is also expedited with the usage of picture archival and communication systems (PACS) by the healthcare service delivery institutions.

Innovations in technology, interventional devices and procedures will surely add to the benefits in the fields of minimally invasive surgery. Multifarious approaches involving usage of more than one imaging modality can aid in the diagnosis of diseases. However, development of appropriate technology, as per the current requirements, which can cover the pit falls in the existing procedures/ techniques/ intervention and standardisation of such interventions can be a challenge. Also, enabling radiologists and surgeons towards adaptability of the newer methods of technology and interventions can be an upfront challenge, as adequate training is of utmost importance in such cases.

As Steve Jobs said, “Everyone here has the sense that right now is one of those moments when we are influencing the future.”

Hence, it can be said that today’s IR certainly shows us a bigger picture of what the future beholds.